enzymes

• all proteins are enzymes but not all enzymes are proteins
• What are enzyme?

  • specialised proteins
  • large and globular
  • catalyse chemical reactions
• What affects enzymes?

  • temperature
  • pH
• Types of enzyme reactions:

  • all enzymes are substrate specific
  • reactions occur due to the lock and key method
  • reactions can be Catabolic (tear down) or Anabolic (build up)
• Enzyme sensitivity to temperature:

  • all enzymes have an optimum temperature
  • if temperature increases past optimum = DENATURATION
  • if temperature decreases below optimum = DEACTIVATION
• Effect of pH on enzyme activity:

  • all enzymes have an optimum pH where their activity is at its highest
  • A deviation, whether higher or lower, will result in DENATURATION of the enzyme and a drop in enzyme activity
• DENATURATION:

  • Structural change in active site
  • Irreversible
• DEACTIVATION:

  • No change in the active site
  • Activity decreases
  • Reversible process
• Enzyme Optimum pH Location

  salivary amylase 7 saliva mouth

  pepsin 2 stomach

  trypsin 8-9 small intestine

  catalase 6-8 liver

  alkaline solution 9 liver
• Temperature is all 37 degrees celsius because that is our body temperature